Question

Select the TWO binomials that will factor the expression: 9x^2-4

3x - 4
3x - 2
3x + 2
2x - 3

Answer 1

Explanation:

a² - b² = (a +b)(a - b)

9x² - 4 = 3²x² - 2²

= (3x)² - 2² {a = 3x; b = 2}

= (3x + 2)(3x - 2)